Tutorial by Examples

With the border-image property you have the possibility to set an image to be used instead of normal border styles. A border-image essentially consist of a border-image-source: The path to the image to be used border-image-slice: Specifies the offset that is used to divide the image into nine r...

cat >file It will let you write the text on terminal which will be saved in a file named file. cat >>file will do the same, except it will append the text to the end of the file. N.B: Ctrl+D to end writing text on terminal (Linux) A here document can be used to inline the content...

app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Home}/{action=Index}/{id?}"); }); This will match requests for /Home/Index, /Home/Index/123 and /

An element's opacity can be set using the opacity property. Values can be anywhere from 0.0 (transparent) to 1.0 (opaque). Example Usage <div style="opacity:0.8;"> This is a partially transparent element </div> Property ValueTransparencyopacity: 1.0;Opaqueopacity: 0....

To create a list of constants - assign iota value to each element: const ( a = iota // a = 0 b = iota // b = 1 c = iota // c = 2 ) To create a list of constants in a shortened way - assign iota value to the first element: const ( a = iota // a = 0 b // b = 1 c /...

iota can be used in expressions, so it can also be used to assign values other than simple incrementing integers starting from zero. To create constants for SI units, use this example from Effective Go: type ByteSize float64 const ( _ = iota // ignore first value by assigning to b...

The value of iota is still incremented for every entry in a constant list even if iota is not used: const ( // iota is reset to 0 a = 1 << iota // a == 1 b = 1 << iota // b == 2 c = 3 // c == 3 (iota is not used but still incremented) d = 1 << iota ...

Because iota is incremented after each ConstSpec, values within the same expression list will have the same value for iota: const ( bit0, mask0 = 1 << iota, 1<<iota - 1 // bit0 == 1, mask0 == 0 bit1, mask1 // bit1 == 2, mask1 == 1 _, _ ...

Iota can be very useful when creating a bitmask. For instance, to represent the state of a network connection which may be secure, authenticated, and/or ready, we might create a bitmask like the following: const ( Secure = 1 << iota // 0b001 Authn // 0b010 Ready ...

Download the Datastax PHP driver for Apache Cassandra from the Git project site, and follow the installation instructions. We will be using the "users" table from the KillrVideo app and the Datastax PHP driver. Once you have Cassandra up and running, create the following keyspace and tabl...

Often times, responsive web design involves media queries, which are CSS blocks that are only executed if a condition is satisfied. This is useful for responsive web design because you can use media queries to specify different CSS styles for the mobile version of your website versus the desktop ver...

Joining on a subquery is often used when you want to get aggregate data (such as Count, Avg, Max, or Min) from a child/details table and display that along with records from the parent/header table. For example, you may want to retrieve the top/first child row based on Date or Id or maybe you want a...

Changing some CSS attribute will trigger the browser to synchronously calculate the style and layout, which is a bad thing when you need to animate at 60fps. DON'T Animate with left and top trigger layout. #box { left: 0; top: 0; transition: left 0.5s, top 0.5s; position: absolute; ...

If you have a multi-parameter type-class with arguments a, b, c, and x, this extension lets you express that the type x can be uniquely identified from a, b, and c: class SomeClass a b c x | a b c -> x where ... When declaring an instance of such class, it will be checked against all other in...

Writes an error message to the console if the assertion is false. Otherwise, if the assertion is true, this does nothing. console.assert('one' === 1); Multiple arguments can be provided after the assertion–these can be strings or other objects–that will only be printed if the assertion is fals...

HTML comments (optionally preceded by whitespace) will cause code (on the same line) to be ignored by the browser also, though this is considered bad practice. One-line comments with the HTML comment opening sequence (<!--): Note: the JavaScript interpreter ignores the closing characters of H...

When developing several applications on one machine, it becomes useful to separate out dependencies into virtual environments. With the use of virtualenv, these environments are sourced into your shell so that when you run a command, it comes from that virtual environment. This is most commonly in...

To setup a new credential profile with the name myprofile: $ aws configure --profile myprofile AWS Access Key ID [None]: ACCESSKEY AWS Secret Access Key [None]: SECRETKEY Default region name [None]: REGIONNAME Default output format [None]: text | table | json For the AWS access key id and se...

Joining a subquery is often used when you want to get aggregate data from a child/details table and display that along with records from the parent/header table. For example, you might want to get a count of child records, an average of some numeric column in child records, or the top or bottom row ...

Activity is the root UserInterface in Android and have it's own life-cycle. MainActivity.java public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Toast.makeText(this, "Activ...